If you have hit solid bedrock you must have 3 feet of compacted clay to seal properly.
At this point, I'm going to throw a monkey wrench in your sheepsfoot compactor vs. a dozer. Before you assume that I'm an idiot and this is my 2nd post I have posted in, I want you to actually think about what I put forward. I was taught earthworks by Geoff Lawton who has constructed ponds all over the world by track rolling only.
According to the University of Missouri
http://extension.missouri.edu/webster/pond-seal.aspxa D-8 has 10-13 pounds per square inch compaction compared to a sheepsfoot roller at 300 psi and a womans high heels at 860 psi +
However not only are these measurement not accurate. There are many variables to consider.
Obviously for the high heels to have such a high psi they are only considering the point of the heel, as they are the points of the sheeps foot roller.
I have a case 1155E track loader at my house so I took some measurements. It's hard to lie with math. The points of the tracks are .5 inches wide and 15.5 inches long. So each track has 7.75 square inches. There are 15 tracks in contact with the ground at a time on each side. The machine weighs 27,362 pounds. Divide that by two and you have, 13,681. 7.75 square inches x 15 equals 116.25. 13,681 lbs divided by 116.25 equals 117.68 pounds per square inch. Much higher then originally suggested per a college study.
I'm a senior master tech that works for Ford motor company. I have every certification you can receive from Ford. I specialize in automatic transmissions, I'm 29 years old. The average age for an automatic transmission specialist is 52.
When people ask me about what direction to face your solar panels, the answer I give is....well it depends.
When people ask me what angle to put your solar panels, the answer is I give is....well it depends.
When people ask me when to change their transmission fluid, the answer I give is....well it depends.
Whether a sheepsfoot compactor is better then track rolling? Well the answer is it depends.
Since i'm an automotive technician, its easy for me to make references to vehicles.
Say we have a 2007 F-350. Have you ever tried to push one in neutral by yourself? Its incredibly difficult by yourself, almost impossible. It weighs around 6,000 lbs. In the diesel model it produces 570 lbs of torque at 2000 rpms. Torque multiplication occurs at lower rpms at 2:1 through the torque converter. The gear ratio for first gear is 3.11 to 1. and the rear end ratio can vary but is common to be 3.73. so 570*2*3.11*3.73= 13,224 foot lbs of torque just to take off. Split that to two wheels and each wheel can receive a max amount of torque of 6,612 lbs just to take off.
If you just measure the vehicles weight, divide it by 4 and calculate the square inches of tire surface you would get a number far inferior to what the vehicle is actually capable of putting to the pavement in terms of force.
The same thing applies to heavy equipment. Can you imagine how much force it takes to move a 27,000 lb piece of equipment, a 40,000 lb piece of equipment? A 60,000 lb piece of equipment? As a machine track rolls and compacts, its not just as simple as the calculation of weight, but the amount of force the tracks put on the ground and compact the soil below it, as it starts and stops, goes forward and backward. As the machine operator drags one brake the force is applied to the front of the inside track and the back of the inside track.
I would suspect in most cases track rolling is far superior to sheepsfoot compaction if the operator knows what he is doing.
But the answer is of course it all depends. If your dragging around a sheepsfoot compacter behind a tractor, of course the track machine is going to compact better. The only exception being an actual dedicated vibratory compaction machine
There have been 100's of thousands of ponds installed that were compacted by track rolling, and it works.